Diabetes Mellitus is known to be associated with certain HLA types. It is also known to cause malformations in infants of diabetic mothers. This study will examine the relationship between HLA "markers" for diabetes and malformatins. The retrospectively ascertained study groups have been HLA typed. There is evidence of a "protective" effect in the DR locus. Although this findng is significant, prospecitvely ascertained population is being enrolled to confirm this finding.